The present invention relates to pumps in general, and more particularly to improvements in diaphragm pumps. Still more particularly, the invention relates to improvements in diaphragm pumps of the type wherein a portion of the diaphragm is flexed back and forth so as to alternately draw and expel a fluid medium from a pumping chamber.
Diaphragm pumps are often utilized to convey metered quantities of fuel or another fluid as well as to serve as so-called vacuum pumps. Reference may be had to French Pat. No. 7,808,069 which discloses a diaphragm pump with an inlet valve and an outlet valve. The diaphragm is flexed back and forth by a rather complex connecting rod which receives motion from a crankshaft and flexes the diaphragm in such a way that the inlet valve opens and admits a supply of fluid when the diaphragm is flexed in one direction whereupon the inlet valve closes and the outlet valve opens in response to increasing pressure in the pumping chamber when the diaphragm is flexed in the opposite direction. In other words, the inlet valve opens when the pressure in the pumping chamber decreases as a result of an increase of the volume of such chamber, and the outlet valve opens automatically in response to increasing pressure in the pumping chamber as a result of a reduction of the volume of such chamber. A drawback of the patented diaphragm pump is that it comprises a substantial number of in part highly complex components. Another drawback of the patented pump is that its components are not readily accessible, and also that the pump must be opened or at least partially dismantled from time to time in order to allow for proper lubrication of certain rotary and/or other components.